code: def tearDownClass(cls):
      ray.shutdown()
  
file_path: ray/rllib/tests/test_algorithm_checkpoint_restore.py
imports: import unittest
  import ray
  from ray.rllib.algorithms.sac import SACConfig
  from ray.rllib.algorithms.ppo import PPOConfig
  from ray.rllib.algorithms.dqn import DQNConfig
  from ray.rllib.utils.test_utils import test_ckpt_restore
  import os
label_desc: Use image node_id 2 for calling the TestCheckpointRestoreOffPolicy obj's underlying member method code with example usage: obj.tearDownClass(cls) without return types